Spin-state selection filters for the measurement of heteronuclear one-bond coupling constants

Novel α/β-half-filter elements are proposed for the separation of the high-field and low-field component of ¹_JHC and ¹J_HN splittings into different subspectra. The α/β-half-filter elements are of the same duration as the S³CT pulse sequence element and, like this, are less sensitive to cross talk between different subspectra than the original shorter α/β-half-filters. The filter elements are demonstrated with the measurement of ¹J_HC coupling constants of C^αH groups in 2D and 3D experiments and the subspectral editing of the four different multiplet components observed in two-dimensional α/β-HSQC-α/β spectra recorded without heteronuclear decoupling in either dimension.